306 Transactions. — Botany, 



Lessonia variegata, J. Ag., Mscr. 



Hah. Plentiful in rock-pools 6ft. to 10ft. or more in depth 

 in the neighbourhood of Wellington (Cook Strait) ; Hoki- 

 anga : Berggrcn. Mr. H. B. Kirk informs me that the plant 

 is also to be seen among the drift-weed on the beaches at 

 Stewart Island. 



General Appearajice. — A bushy plant, 3ft. to 5ft. high, 

 bearing at the top of its numerous stems a subglobose mass 

 of fronds a foot or two in diameter. It grows below low- 

 water mark, so that the tops of the leaves just reach the 

 surface at low tide. Small specimens may occasionally be 

 obtained which are completely uncovered at ebb. 



TJie Bhizoid. — In the young plant the root consists of a 

 number of short, dichotomous branches, the tips of which are 

 closely appressed to the rock-surface (PI. XXXIX., fig. 1, a). 

 When the plant is torn off it generally brings with it a more or 

 less complete disc of rock-chips, corallines, and other incrusta- 

 tions attached to the root-tips. In the mature plants, owing 

 to the coalescence of adjacent roots, the expansion of the 

 lower branches, and the growth of numerous adventitious 

 rootlets from the lower ends of the stem, the main rhizoid 

 tends to form a ribbed columnar mass (PI. XL., fig. 1, a). This 

 forms a favourite resort for numerous epiphytic and parasitic 

 growths of sponges, zoophytes, sertularians, corallines, 

 floridese, &c. 



The Branch System. — Immediately above the root, even in 

 young plants, a number of branches are given off, which are 

 more or less compressed or oval in transverse section, and 

 from lin. to l^in. in width in the direction of the longer 

 diameter. Each branch divides three or four times dichotom- 

 ously at an acute angle, broadening out a little below each 

 fork, and finally each branchlet terminates in a frond. The 

 pseudo-petioles are twisted several times below each frond, and 

 the twisting is continued for some distance towards the base. 

 The total length of the branching system is from 2ft. to 3ft. 

 New branches are formed thus: A small fissure appears just 

 where the frond joins the top of the stipe. This gradually 

 extends through the lamina until bisection is completed. Oc- 

 casionally a secondary fission commences before the primary 

 one is completed (PI. XL., fig. 2). 



The Fronds. — These are from 1ft. to 2ft. in length, and lin. 

 or 2in. in breadth, linear or linear-oblong, sometimes falcate 

 owing to unilateral growth, and with a few teeth scattered 

 along the margin. In the young plant they are generally 

 much longer than in the mature plant, with acuminate apices, 

 as may be seen by a reference to the plates. The probable 

 explanation of tliis will be given presently. They are olive- 



